How Bachelorette Couple Shawn Booth and Kaitlyn Bristowe Are Working T…

Shawn Booth was the last man standing on season 19 of The Bachelorette, and now, he’s vying for the finish line in a much different race.

The personal trainer is amping up for his first-ever Ironman this July in Lake Placid, New York, and says his intense training regimen has totally taken over.

“It’s definitely a commitment to stay on top of my training, but we’re getting there,” Booth tells PEOPLE of working out at least two times a day.

An Ironman is not for the faint of heart: “It starts off with a 2.4 mile swim, and then after that you get out of the water and do a 112 mile bike ride, and then right after the bike ride you go into a full marathon run, which is 26.2 miles,” Booth says.

Luckily, Booth has a great cheering squad – and teammate – in fiancée Kaitlyn Bristowe, who presented the 31-year-old with her final rose on the reality dating series in 2015.

Bristowe has particularly taken to helping Booth navigate his new diet, which he says is centered around “the good carbs, good fats and a ton of calories.”

“I’m eating anywhere between six to eight meals a day, and that’s why I have this beautiful lady with me who likes to help me out with the cooking,” he says.

Joking that their grocery bill has become “insane,” Bristowe says, “I do enjoy cooking his meals for him.”

But getting used to their new lifestyle hasn’t been all smooth sailing. Bristowe, 31, says that sharing a vehicle with her fiancé when he’s at the gym for hours at a time can make for a carpooling challenge.

“Before he started doing training, though, we spent every second of every day together, so now he goes away and he’s like gone for the day and I’m like, ‘Hey, I miss you!’ ” she says.

Of Off the Vine, Bristowe says, “I’m like kind of an open book and I’ll talk about anything.” She explains, “Basically, the podcast is supposed to be an hour or 45 minutes of just fun.”

Booth – who is also raising money for K9s For Warriors as part of his race – is also happy to provide guidance for anyone considering taking on the challenge of an Ironman.

“I think the hardest part would be getting into the right mentality,” he admits. “I think that’s the number one thing you need to complete an Ironman: stay positive throughout the training. Do what you need to do, put in the work, eat the right food, and just get after it.”